Detection device and method for manufacturing the same

ABSTRACT

According to an aspect, a detection device includes: a substrate; a plurality of photodiodes arranged on a first principal surface of the substrate; a protective film that covers the photodiodes; a plurality of lenses provided for each of the photodiodes so as to face the photodiode with the protective film interposed between the lenses and the photodiodes; and a projection provided between the lenses. A top of the projection is located at a position higher than a top of each of the lenses when viewed from the first principal surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from Japanese PatentApplication No. 2020-161107 filed on Sep. 25, 2020, the entire contentsof which are incorporated herein by reference.

BACKGROUND 1. Technical Field

What is disclosed herein relates to a detection device and a method formanufacturing the same.

2. Description of the Related Art

United States Patent Application Publication No. 2020/0089928 describesan optical imaging device that includes a light-blocking layer providedwith an opening between a microlens and a photosensor. Apositive-intrinsic-negative (PIN) photodiode is known as such aphotosensor.

A detection device using the PIN photodiode is required to be madethinner. The detection device is formed of a single array substrateprovided with a plurality of photodiodes and a plurality of microlenses.In this case, the substrate may be difficult to be polished because, forexample, the microlenses formed on the array substrate are damaged in apolishing process of the substrate.

SUMMARY

According to an aspect, a detection device includes: a substrate; aplurality of photodiodes arranged on a first principal surface of thesubstrate; a protective film that covers the photodiodes; a plurality oflenses provided for each of the photodiodes so as to face the photodiodewith the protective film interposed between the lenses and thephotodiodes; and a projection provided between the lenses. A top of theprojection is located at a position higher than a top of each of thelenses when viewed from the first principal surface.

According to an aspect, a method for manufacturing a detection device,the detection device including a substrate, a plurality of photodiodesarranged on a first principal surface of the substrate, a protectivefilm provided on the substrate so as to cover the photodiodes, and aplurality of lenses provided for each of the photodiodes so as tooverlap the photodiode, the method includes: stacking a pair of thesubstrates together, with the first principal surfaces of the pair ofthe substrates facing each other, the substrates each having aprojection formed on the substrate, the projection having a heightgreater than a height of the lenses in a direction orthogonal to thesubstrate; and polishing a second principal surface on an opposite sideof the first principal surface of each of the substrates in a statewhere the pair of the substrates are stacked together. At the stackingthe pair of the substrates together, the projection of one of thedetection devices abuts on a portion of another of the detection devicesfacing the one detection device, and the lenses of the one detectiondevice face the lenses of the other detection device without contactingone another.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a sectional view illustrating a schematic sectionalconfiguration of a detection apparatus with an illumination device, thedetection apparatus including a detection device according to anembodiment;

FIG. 1B is a sectional view illustrating a schematic sectionalconfiguration of the detection apparatus with an illumination device,the detection apparatus including the detection device according to afirst modification;

FIG. 1C is a sectional view illustrating a schematic sectionalconfiguration of the detection apparatus with an illumination device,the detection apparatus including the detection device according to asecond modification;

FIG. 1D is a sectional view illustrating a schematic sectionalconfiguration of the detection apparatus with an illumination device,the detection apparatus including the detection device according to athird modification;

FIG. 2 is a plan view illustrating the detection device according to theembodiment;

FIG. 3 is a block diagram illustrating a configuration example of thedetection device according to the embodiment;

FIG. 4 is a circuit diagram illustrating a detection element;

FIG. 5 is a plan view illustrating the detection element;

FIG. 6 is a VI-VI′ sectional view of FIG. 5;

FIG. 7 is a VII-VII′ sectional view of FIG. 5;

FIG. 8 is a plan view illustrating a configuration example of an opticalfilter and projections;

FIG. 9 is a IX-IX′ sectional view of FIG. 8;

FIG. 10 is a flowchart for explaining a method for manufacturing thedetection device according to the embodiment;

FIG. 11 is a perspective view schematically illustrating a pair ofbonded motherboards;

FIG. 12 is a XII-XII′ sectional view of FIG. 11;

FIG. 13 is a sectional view schematically illustrating a configurationof an array substrate bonded to a display panel;

FIG. 14 is a flowchart for explaining a method for manufacturing thedetection device according a fourth modification of the embodiment;

FIG. 15 is a sectional view schematically illustrating a detectiondevice according a fifth modification of the embodiment;

FIG. 16 is a sectional view schematically illustrating a detectiondevice according a sixth modification of the embodiment;

FIG. 17 is a plan view schematically illustrating a detection deviceaccording a seventh modification of the embodiment;

FIG. 18 is a plan view schematically illustrating a detection deviceaccording an eighth modification of the embodiment; and

FIG. 19 is a sectional view for explaining a method for manufacturingthe detection device according the eighth modification.

DETAILED DESCRIPTION

The following describes a mode (embodiment) for carrying out the presentdisclosure in detail with reference to the drawings. The presentdisclosure is not limited to the description of the embodiment givenbelow. Components described below include those easily conceivable bythose skilled in the art or those substantially identical thereto. Inaddition, the components described below can be combined as appropriate.What is disclosed herein is merely an example, and the presentdisclosure naturally encompasses appropriate modifications easilyconceivable by those skilled in the art while maintaining the gist ofthe disclosure. To further clarify the description, widths, thicknesses,shapes, and the like of various parts may be schematically illustratedin the drawings as compared with actual aspects thereof. However, theyare merely examples, and interpretation of the present disclosure is notlimited thereto. The same component as that described with reference toan already mentioned drawing is denoted by the same reference numeralthrough the disclosure and the drawings, and detailed descriptionthereof may not be repeated where appropriate.

In the present specification and claims, in expressing an aspect ofdisposing another structure on or above a certain structure, a case ofsimply expressing “on” includes both a case of disposing the otherstructure immediately on the certain structure such that the otherstructure contacts the certain structure and a case of disposing theother structure above the certain structure with still another structureinterposed therebetween, unless otherwise specified.

FIG. 1A is a sectional view illustrating a schematic sectionalconfiguration of a detection apparatus with an illumination device, thedetection apparatus including a detection device according to anembodiment of the present disclosure. FIG. 1B is a sectional viewillustrating a schematic sectional configuration of the detectionapparatus with an illumination device, the detection apparatus includingthe detection device according to a first modification of theembodiment. FIG. 1C is a sectional view illustrating a schematicsectional configuration of the detection apparatus with an illuminationdevice, the detection apparatus including the detection device accordingto a second modification of the embodiment. FIG. 1D is a sectional viewillustrating a schematic sectional configuration of the detectionapparatus with an illumination device, the detection apparatus includingthe detection device according to a third modification of theembodiment.

As illustrated in FIG. 1A, a detection apparatus 120 with anillumination device includes a detection device 1 and an illuminationdevice 121. The detection device 1 includes a sensor substrate 5, anoptical filter 7, an adhesive layer 125, and a cover member 122. Thatis, the sensor substrate 5, the optical filter 7, the adhesive layer125, and the cover member 122 are stacked in the order as listed, in adirection orthogonal to a surface of the sensor substrate 5. The covermember 122 of the detection device 1 can be replaced with theillumination device 121, as will be described later. The adhesive layer125 only needs to bond the optical filter 7 to the cover member 122.Hence, the detection device 1 may have a structure without the adhesivelayer 125 in a region corresponding to a detection region AA. When theadhesive layer 125 is absent in the detection region AA, the detectiondevice 1 has a structure in which the adhesive layer 125 bonds the covermember 122 to the optical filter 7 in a region corresponding to aperipheral region GA outside the detection region AA. The adhesive layer125 provided in the detection region AA may be simply paraphrased as aprotective layer for the optical filter 7.

As illustrated in FIG. 1A, the illumination device 121 may be, forexample, what is called a side light-type front light that uses thecover member 122 as a light guide plate provided at a locationcorresponding to a detection region AA of the detection device 1, andthat includes a plurality of light sources 123 arranged side by side atone end or both ends of the cover member 122. That is, the cover member122 has a light-emitting surface 121 a for emitting light, and serves asone component of the illumination device 121. The illumination device121 emits light L1 from the light-emitting surface 121 a of the covermember 122 toward a finger Fg serving as a detection target. Forexample, light-emitting diodes (LEDs) for emitting light in apredetermined color are used as the light sources.

As illustrated in FIG. 1B, the illumination device 121 may include lightsources (such as LEDs) provided immediately below the detection regionAA of the detection device 1, and the illumination device 121 includingthe light sources serves also as the cover member 122.

The illumination device 121 is not limited to the example of FIG. 1B. Asillustrated in FIG. 1C, the illumination device 121 may be provided on alateral side of or above the cover member 122, and may emit the light L1to the finger Fg from the lateral side of or above the finger Fg.

Furthermore, as illustrated in FIG. 1D, the illumination device 121 maybe what is called a direct-type backlight that includes light sources(such as LEDs) provided in the detection region of the detection device1.

The light L1 emitted from the illumination device 121 is reflected aslight L2 by the finger Fg serving as the detection target. The detectiondevice 1 detects the light L2 reflected by the finger Fg (shading of thelight L2 or an intensity of the reflected light) to detect asperities(such as a fingerprint) on the surface of the finger Fg. The detectiondevice 1 may further detect the light L2 reflected inside the finger Fgto detect information on a living body in addition to detecting thefingerprint. Examples of the information on the living body include ablood vessel image of, for example, a vein, pulsation, and a pulse wave.The color of the light L1 from the illumination device 121 may be varieddepending on the detection target.

The cover member 122 is a member for protecting the sensor substrate 5and the optical filter 7, and covers the sensor substrate 5 and theoptical filter 7. The illumination device 121 may have a structure todouble as the cover member 122 as described above. In the structuresillustrated in FIGS. 1C and 1D in which the cover member 122 is separatefrom the illumination device 121, the cover member 122 is, for example,a glass substrate. The cover member 122 is not limited to the glasssubstrate, and may be, for example, a resin substrate or may have aconfiguration including a plurality of layers obtained by stacking thesesubstrates. The cover member 122 need not be provided. In this case, thesurfaces of the sensor substrate 5 and the optical filter 7 are providedwith a protective layer of, for example, an insulating film, and thefinger Fg contacts the protective layer of the detection device 1.

As illustrated in FIG. 1B, the detection apparatus 120 with anillumination device may be provided with a display panel 126 instead ofthe illumination device 121. The display panel 126 may be, for example,an organic electroluminescent (EL) diode (organic light-emitting diode(OLED)) display panel or an inorganic EL display (micro-LED ormini-LED). Alternatively, the display panel 126 may be a liquid crystaldisplay (LCD) panel using liquid crystal elements as display elements oran electrophoretic display (EPD) panel using electrophoretic elements asthe display elements. In this case, display light (light L1) emittedfrom the display panel 126 is reflected by the finger Fg, and thereflected light passes through the display panel 126 to reach theoptical filter 7. In view of this fact, the display panel 126 ispreferably configured with a substrate or a multilayered film havinglight transmissivity. The fingerprint of the finger Fg and theinformation on the living body can be detected based on the light L2.

FIG. 2 is a plan view illustrating the detection device according to theembodiment. A first direction Dx illustrated in FIG. 2 and thesubsequent drawings is one direction in a plane parallel to a substrate21. A second direction Dy is a direction in the plane parallel to thesubstrate 21 and is a direction orthogonal to the first direction Dx.The second direction Dy may intersect the first direction Dx withoutbeing orthogonal thereto. A third direction Dz is a direction orthogonalto the first direction Dx and the second direction Dy and is a directionnormal to the substrate 21.

As illustrated in FIG. 2, the detection device 1 includes an arraysubstrate 2 (substrate 21), a sensor 10, a scan line drive circuit 15, asignal line selection circuit 16, a detection circuit 48, a controlcircuit 102, and a power supply circuit 103.

The substrate 21 is electrically coupled to a control substrate 101through a wiring substrate 110. The wiring substrate 110 is, forexample, a flexible printed circuit board or a rigid circuit board. Thewiring substrate 110 is provided with the detection circuit 48. Thecontrol substrate 101 is provided with the control circuit 102 and thepower supply circuit 103. The control circuit 102 is, for example, afield-programmable gate array (FPGA). The control circuit 102 suppliescontrol signals to the sensor 10, the scan line drive circuit 15, andthe signal line selection circuit 16 to control operations of the sensor10. The power supply circuit 103 supplies voltage signals including, forexample, a power supply potential VDD and a reference potential VCOM(refer to FIG. 4) to the sensor 10, the scan line drive circuit 15, andthe signal line selection circuit 16. Although the present embodimentexemplifies the case of disposing the detection circuit 48 on the wiringsubstrate 110, the present disclosure is not limited to this case. Thedetection circuit 48 may be disposed on the substrate 21.

The substrate 21 has the detection region AA and the peripheral regionGA. The detection region AA and the peripheral region GA extend inplanar directions parallel to the substrate 21. Elements (detectionelements 3) of the sensor 10 are provided in the detection region AA.The peripheral region GA is a region outside the detection region AA andis a region not provided with the elements (detection elements 3). Thatis, the peripheral region GA is a region between the outer circumferenceof the detection region AA and outer edges of the substrate 21. The scanline drive circuit 15 and the signal line selection circuit 16 areprovided in the peripheral region GA. The scan line drive circuit 15 isprovided in a region extending along the second direction Dy in theperipheral region GA. The signal line selection circuit 16 is providedin a region extending along the first direction Dx in the peripheralregion GA, and is provided between the sensor 10 and the detectioncircuit 48.

Each of the detection elements 3 of the sensor 10 is a photosensorincluding a photodiode 30 as a sensor element. The photodiode 30 is aphotoelectric conversion element, and outputs an electrical signalcorresponding to light irradiating each of the photodiodes 30. Morespecifically, the photodiode 30 is a positive-intrinsic-negative (PIN)photodiode. The photodiode 30 may be paraphrased as an organicphotodiode (OPD). The detection elements 3 are arranged in a matrixhaving a row-column configuration in the detection region AA. Thephotodiode 30 included in each of the detection elements 3 performs thedetection in accordance with a gate drive signal (for example, a resetcontrol signal RST or a read control signal RD) supplied from the scanline drive circuit 15. Each of the photodiodes 30 outputs the electricalsignal corresponding to the light irradiating the photodiode 30 as adetection signal Vdet to the signal line selection circuit 16. Thedetection device 1 detects the information on the living body based onthe detection signals Vdet received from the photodiodes 30.

FIG. 3 is a block diagram illustrating a configuration example of thedetection device according to the embodiment. As illustrated in FIG. 3,the detection device 1 further includes a detection control circuit 11and a detector 40. One, some, or all functions of the detection controlcircuit 11 are included in the control circuit 102. One, some, or allfunctions of the detector 40 other than those of the detection circuit48 are also included in the control circuit 102.

The detection control circuit 11 supplies control signals to the scanline drive circuit 15, the signal line selection circuit 16, and thedetector 40 to control operations of these components. The detectioncontrol circuit 11 supplies various control signals including, forexample, a start signal STV and a clock signal CK to the scan line drivecircuit 15. The detection control circuit 11 also supplies variouscontrol signals including, for example, a selection signal ASW to thesignal line selection circuit 16.

The scan line drive circuit 15 drives a plurality of scan lines (readcontrol scan line GLrd and reset control scan lines GLrst (refer to FIG.4)) based on the various control signals. The scan line drive circuit 15sequentially or simultaneously selects the scan lines, and supplies thegate drive signal (for example, the reset control signal RST or the readcontrol signal RD) to the selected scan lines. Through this operation,the scan line drive circuit 15 selects the photodiodes 30 coupled to thescan lines.

The signal line selection circuit 16 is a switching circuit thatsequentially or simultaneously selects output signal lines SL (refer toFIG. 4). The signal line selection circuit 16 is, for example, amultiplexer. The signal line selection circuit 16 couples the selectedoutput signal lines SL to the detection circuit 48 based on theselection signal ASW supplied from the detection control circuit 11.Through this operation, the signal line selection circuit 16 outputs thedetection signal Vdet of the photodiode 30 to the detector 40.

The detector 40 includes the detection circuit 48, a signal processingcircuit 44, a coordinate extraction circuit 45, a storage circuit 46,and a detection timing control circuit 47. The detection timing controlcircuit 47 performs control to cause the detection circuit 48, thesignal processing circuit 44, and the coordinate extraction circuit 45to operate in synchronization with one another based on a control signalsupplied from the detection control circuit 11.

The detection circuit 48 is, for example, an analog front end (AFE)circuit. The detection circuit 48 is a signal processing circuit havingfunctions of at least a detection signal amplifying circuit 42 and ananalog-to-digital (A/D) conversion circuit 43. The detection signalamplifying circuit 42 is a circuit that amplifies the detection signalVdet, and is, for example, an integration circuit. The A/D conversioncircuit 43 converts an analog signal output from the detection signalamplifying circuit 42 into a digital signal.

The signal processing circuit 44 is a logic circuit that detects apredetermined physical quantity received by the sensor 10 based onoutput signals of the detection circuit 48. The signal processingcircuit 44 can detect asperities on a surface of the finger Fg or a palm(fingerprint or palm print) based on the signals from the detectioncircuit 48 when the finger Fg is in contact with or in proximity to adetection surface. The signal processing circuit 44 may detect theinformation on the living body based on the signals from the detectioncircuit 48. Examples of the information on the living body include ablood vessel image of the finger Fg or the palm, a pulse wave,pulsation, and blood oxygen saturation.

The storage circuit 46 temporarily stores therein signals calculated bythe signal processing circuit 44. The storage circuit 46 may be, forexample, a random-access memory (RAM) or a register circuit.

The coordinate extraction circuit 45 is a logic circuit that obtainsdetected coordinates of the asperities on the surface of the finger Fgor the like when the contact or proximity of the finger Fg is detectedby the signal processing circuit 44. The coordinate extraction circuit45 is the logic circuit that also obtains detected coordinates of bloodvessels of the finger Fg or the palm. The coordinate extraction circuit45 combines the detection signals Vdet output from the respectivedetection elements 3 of the sensor 10 to generate two-dimensionalinformation representing a shape of the asperities on the surface of thefinger Fg or the like. The coordinate extraction circuit 45 may outputthe detection signals Vdet as sensor outputs Vo instead of calculatingthe detected coordinates.

The following describes a circuit configuration example of the detectiondevice 1. FIG. 4 is a circuit diagram illustrating the detectionelement. As illustrated in FIG. 4, the detection element 3 includes thephotodiode 30, a reset transistor Mrst, a read transistor Mrd, and asource follower transistor Msf. The reset transistor Mrst, the readtransistor Mrd, and the source follower transistor Msf are providedcorrespondingly to each of the photodiodes 30. Each of the resettransistor Mrst, the read transistor Mrd, and the source followertransistor Msf is made up of an n-type thin-film transistor (TFT).However, each of the transistors is not limited thereto, and may be madeup of a p-type TFT.

The reference potential VCOM is applied to an anode of the photodiode30. A cathode of the photodiode 30 is coupled to a node N1. The node N1is coupled to a capacitance Cs, one of the source and the drain of thereset transistor Mrst, and the gate of the source follower transistorMsf. In addition, the node N1 has parasitic capacitance Cp. When lightenters the photodiode 30, a signal (electrical charge) output from thephotodiode 30 is stored in the capacitance Cs.

The capacitance Cs is, for example, capacitance generated between ap-type semiconductor layer 33 and an n-type semiconductor layer 32 ofthe photodiode 30 (refer to FIG. 6). The parasitic capacitance Cp iscapacitance added to the capacitance Cs, and is also capacitancegenerated among various types of wiring and electrodes provided on thearray substrate 2.

The gates of the reset transistor Mrst are coupled to the reset controlscan line GLrst. The other of the source and the drain of the resettransistor Mrst is supplied with a reset potential Vrst. When the resettransistor Mrst is turned on (into a conduction state) in response tothe reset control signal RST, the potential of the node N1 is reset tothe reset potential Vrst. The reference potential VCOM is lower than thereset potential Vrst, and the photodiode 30 is driven in a reverse biasstate.

The source follower transistor Msf is coupled between a terminalsupplied with the power supply potential VDD and the read transistor Mrd(node N2). The gate of the source follower transistor Msf is coupled tothe node N1. The gate of the source follower transistor Msf is suppliedwith the signal (electrical charge) generated by the photodiode 30. Thisoperation causes the source follower transistor Msf to output a voltagesignal corresponding to the signal (electrical charge) generated by thephotodiode 30 to the read transistor Mrd.

The read transistor Mrd is coupled between the source of the sourcefollower transistor Msf (node N2) and the output signal line SL (nodeN3). The gates of the read transistor Mrd are coupled to the readcontrol scan line GLrd. When the read transistor Mrd is turned on inresponse to the read control signal RD, the signal output from thesource follower transistor Msf, that is, the voltage signalcorresponding to the signal (electrical charge) generated by thephotodiode 30 is output as the detection signal Vdet to the outputsignal line SL.

In the example illustrated in FIG. 4, the reset transistor Mrst and theread transistor Mrd each have what is called a double-gate structureconfigured by coupling two transistors in series. However, the resettransistor Mrst and the read transistor Mrd are not limited to thisstructure, and may have a single-gate structure, or a multi-gatestructure including three or more transistors coupled in series. Thecircuit of the detection element 3 is not limited to the configurationincluding the three transistors of the reset transistor Mrst, the sourcefollower transistor Msf, and the read transistor Mrd. The detectionelement 3 may include two transistors, or four or more transistors.

The following describes a planar configuration and a sectionalconfiguration of the detection element 3. FIG. 5 is a plan viewillustrating the detection element. As illustrated in FIG. 5, thedetection element 3 includes two scan lines (the read control scan lineGLrd and the reset control scan line GLrst) and four signal lines (theoutput signal line SL, a power supply signal line SLsf, a reset signalline SLrst, and a reference signal line SLcom).

The read control scan line GLrd and the reset control scan line GLrstextend in the first direction Dx and are arranged in the seconddirection Dy. The output signal line SL, the power supply signal lineSLsf, the reset signal line SLrst, and the reference signal line SLcomextend in the second direction Dy and are arranged in the firstdirection Dx.

The detection element 3 is defined as a region surrounded by the twoscan lines (the read control scan line GLrd and the reset control scanline GLrst) and two signal lines (for example, two power supply signallines SLsf of the adjacent detection elements 3).

As illustrated in FIG. 5, the photodiode 30 includes a plurality ofpartial photodiodes 30S-1, 30S-2, . . . , 30S-8. The partial photodiodes30S-1, 30S-2, . . . , 30S-8 are arranged in a triangular latticepattern.

A lense 78 of the optical filter 7, a first opening OP1 of a firstlight-blocking layer 71, and a second opening OP2 of a secondlight-blocking layer 72 illustrated in FIG. 9 are provided so as tooverlap each of the partial photodiodes 30S-1, 30S-2, . . . , 30S-8. Forease of viewing, FIG. 5 illustrates only the first openings OP1 amongthe components of the optical filter 7.

More specifically, the partial photodiodes 30S-1, 30S-2, and 30S-3 arearranged in the second direction Dy. The partial photodiodes 30S-4 and30S-5 are arranged in the second direction Dy and are adjacent to anelement column made up of the partial photodiodes 30S-1, 30S-2, and30S-3 in the first direction Dx. The partial photodiodes 30S-6, 30S-7,and 30S-8 are arranged in the second direction Dy and are adjacent to anelement column made up of the partial photodiodes 30S-4 and 30S-5 in thefirst direction Dx. The partial photodiodes 30S are arranged atstaggered positions in the second direction Dy between the adjacentelement columns.

The light L2 is incident on the partial photodiodes 30S-1, 30S-2, . . ., 30S-8 through the optical filter 7. The partial photodiodes 30S-1,30S-2, . . . , 30S-8 are electrically coupled to one another to serve asone photodiode 30. That is, signals output from the respective partialphotodiodes 30S-1, 30S-2, . . . , 30S-8 are integrated into onedetection signal Vdet to be output from the photodiode 30. In thefollowing description, the partial photodiodes 30S-1, 30S-2, . . . ,30S-8 will be simply referred to as “partial photodiodes 30S” when neednot be distinguished from one another.

Each of the partial photodiodes 30S includes an i-type semiconductorlayer 31, the n-type semiconductor layer 32, and the p-typesemiconductor layer 33. The i-type semiconductor layer 31 and the n-typesemiconductor layer 32 are, for example, of amorphous silicon (a-Si).The p-type semiconductor layer 33 is, for example, of polysilicon(p-Si). The material of each of the semiconductor layers is not limitedto those mentioned above and may be, for example, polysilicon ormicrocrystalline silicon.

The a-Si of the n-type semiconductor layer 32 is doped with impuritiesto form an n+ region. The p-Si of the p-type semiconductor layer 33 isdoped with impurities to form a p+ region. The i-type semiconductorlayer 31 is, for example, a non-doped intrinsic semiconductor and haslower conductivity than that of the n-type semiconductor layer 32 andthe p-type semiconductor layer 33.

In FIG. 5, a dotted line indicates a first region R1 serving as aneffective sensor region in which the p-type semiconductor layer 33 andthe i-type semiconductor layer 31 (and the n-type semiconductor layer32) overlap each other and are directly coupled together. Each of thepartial photodiodes 30S includes at least the first region R1. In otherwords, the first regions R1 are arranged in a triangular lattice patternin a plan view. Each of the first openings OP1 of the optical filter 7is provided so as to overlap the first region R1.

Each of the partial photodiodes 30S is formed in a circular shape or asemi-circular shape in the plan view. The shape of the partialphotodiode 30S is, however, not limited thereto, and may be, forexample, a polygonal shape. The partial photodiodes 30S may have shapesdifferent from one another.

The n-type semiconductor layers 32 of the partial photodiodes 30S-1,30S-2, and 30S-3 arranged in the second direction Dy are electricallycoupled to one another through a joint CA1. The p-type semiconductorlayers 33 of the partial photodiodes 30S-1, 30S-2, and 30S-3 areelectrically coupled to one another through a joint CA2.

The n-type semiconductor layers 32 (i-type semiconductor layers 31) ofthe partial photodiodes 30S-4, 30S-5, 30S-6, 30S-7, and 30S-8 areelectrically coupled to one another through a base BA1. The p-typesemiconductor layers 33 of the partial photodiodes 30S-4, 30S-5, 30S-6,30S-7, and 30S-8 are electrically coupled to one another through a baseBA2. Each of the base BA1 and the base BA2 is formed in a substantiallypentagonal shape and is provided, at the apex positions thereof, withthe partial photodiodes 30S-4, 30S-5, 30S-6, 30S-7, and 30S-8.

The base BA1 is disposed so as to be separated in the first direction Dxfrom the i-type semiconductor layers 31 and the n-type semiconductorlayers 32 of the partial photodiodes 30S-1, 30S-2, and 30S-3. The baseBA2 coupled to the p-type semiconductor layers 33 of the partialphotodiodes 30S-4, 30S-5, 30S-6, 30S-7, and 30S-8 is electricallycoupled to the p-type semiconductor layers 33 of the partial photodiodes30S-1, 30S-2, and 30S-3 through a joint CA2 a passing below the resetsignal line SLrst and the reference signal line SLcom along the firstdirection Dx. As a result, the partial photodiodes 30S constituting onephotodiode 30 are electrically coupled to one another.

A lower conductive layer 35 is provided in a region overlapping thepartial photodiodes 30S, the joints CAL CA2, and CA2 a, and the basesBA1 and BA2. Portions of the lower conductive layer 35 overlapping therespective partial photodiodes 30S are formed in a circular shape.However, the portions of the lower conductive layer 35 may have adifferent shape from that of the partial photodiode 30S. The lowerconductive layer 35 only needs to be provided in portions overlapping atleast the first regions R1. The lower conductive layer 35 is suppliedwith the reference potential VCOM that is the same as the potential ofthe p-type semiconductor layer 33, and thus can reduce the parasiticcapacitance between the lower conductive layer 35 and the p-typesemiconductor layer 33.

An upper conductive layer 34 electrically couples the n-typesemiconductor layers 32 of the partial photodiodes 30S to one another.Specifically, the upper conductive layer 34 is electrically coupled tothe n-type semiconductor layers 32 of the respective partial photodiodes30S-1 and 30S-3 through contact holes H1 and H2 provided in aninsulating film 27 (refer to FIG. 6), at positions overlapping thepartial photodiodes 30S-1 and 30S-3. A coupling portion 34 a of theupper conductive layer 34 is formed in a T-shape so as to overlap thejoints CAL CA2, and CA2 a and the partial photodiode 30S-2, and iscoupled to a coupling portion 34 b. The coupling portion 34 b of theupper conductive layer 34 is electrically coupled to the n-typesemiconductor layer 32 of the base BA1 through a contact hole H3provided in the insulating film 27 (refer to FIG. 6), at a positionoverlapping the base BA1.

In addition, the upper conductive layer 34 extends from the couplingportion 34 b to a region not overlapping the photodiode 30 and iscoupled to a coupling portion 34 c. The coupling portion 34 c of theupper conductive layer 34 is electrically coupled to the transistors(the reset transistor Mrst and the source follower transistor Msf (referto FIG. 4)) through a contact hole H4. The upper conductive layer 34 maybe provided in any manner, and may be provided, for example, so as topartially cover the partial photodiodes 30S, or so as to fully cover thepartial photodiodes 30S.

The reset transistor Mrst, the source follower transistor Msf, and theread transistor Mrd are provided in the region not overlapping thephotodiode 30. The source follower transistor Msf and the readtransistor Mrd are provided, for example, adjacent to the photodiode 30in the first direction Dx. The reset transistor Mrst is providedadjacent to the partial photodiode 30S-4 in the second direction Dy andis provided between the partial photodiode 30S-1 and the partialphotodiode 30S-6 in the first direction Dx.

One end of a semiconductor layer 61 of the reset transistor Mrst iscoupled to the reset signal line SLrst. The other end of thesemiconductor layer 61 is coupled to coupling wiring SLcn3 (node N1)through a contact hole H17 (refer to FIG. 7). A portion of the resetsignal line SLrst coupled to the semiconductor layer 61 serves as asource electrode, and a portion of the coupling wiring SLcn3 coupled tothe semiconductor layer 61 serves as a drain electrode 63 (refer to FIG.7). The semiconductor layer 61 is formed in a U-shape and intersects thereset control scan line GLrst at two locations. Channel regions areformed in portions of the semiconductor layer 61 overlapping the resetcontrol scan line GLrst, and portions of the reset control scan lineGLrst overlapping the semiconductor layer 61 serve as respective gateelectrodes 64.

The source follower transistor Msf includes a semiconductor layer 65, asource electrode 66, a drain electrode 67, and a gate electrode 68. Oneend of the semiconductor layer 65 is coupled to the power supply signalline SLsf through a contact hole H15 (refer to FIG. 6). The other end ofthe semiconductor layer 65 is coupled to coupling wiring SLcn1 (node N2)through a contact hole H16 (refer to FIG. 6). A portion of the powersupply signal line SLsf coupled to the semiconductor layer 65 serves asthe drain electrode 67, and a portion of the coupling wiring SLcn1coupled to the semiconductor layer 65 serves as the source electrode 66.

One end side of the gate electrode 68 extends in the first direction Dxand overlaps the semiconductor layer 65. The other end side of the gateelectrode 68 extends in the second direction Dy and is electricallycoupled to the coupling wiring SLcn3. This configuration electricallycouples the reset transistor Mrst to the gate of the source followertransistor Msf through the coupling wiring SLcn3.

The read transistor Mrd includes a semiconductor layer 81, a sourceelectrode 82, a drain electrode 83, and gate electrodes 84. One end ofthe semiconductor layer 81 is coupled to the coupling wiring SLcn1. Theother end of the semiconductor layer 81 is coupled to coupling wiringSLcn2 branching in the first direction Dx from the output signal lineSL. A portion of the coupling wiring SLcn1 coupled to the semiconductorlayer 81 serves as the drain electrode 83, and a portion of the couplingwiring SLcn2 coupled to the semiconductor layer 81 serves as the sourceelectrode 82. The two gate electrodes 84 are arranged in the seconddirection Dy and overlap the semiconductor layer 81. The two gateelectrodes 84 are electrically coupled to the read control scan lineGLrd through a branch that extends in the second direction Dy andoverlaps the power supply signal line SLsf. The above-describedconfiguration couples the source follower transistor Msf and the readtransistor Mrd to the output signal line SL.

The output signal line SL is disposed between the position of the sourcefollower transistor Msf and the read transistor Mrd and the position ofthe partial photodiodes 30S-6, 30S-7, and 30S-8. The output signal lineSL is provided in a zig-zag manner along the partial photodiodes 30S-6,30S-7, and 30S-8.

The reset signal line SLrst and the reference signal line SLcom aredisposed between the position of the partial photodiodes 30S-1, 30S-2,and 30S-3 and the position of the partial photodiodes 30S-4 and 30S-5.The reset signal line SLrst and the reference signal line SLcom areprovided in a zig-zag manner along the partial photodiodes 30S andintersect the joint CA2 a. Since the partial photodiodes 30S-1, 30S-2,and 30S-3 are coupled to the partial photodiodes 30S-4 and 30S-5 throughthe joint CA2 a, the parasitic capacitance of the reset signal lineSLrst and the reference signal line SLcom can be smaller than that of aconfiguration in which the bases BA1 and BA2 are provided so as tooverlap the reset signal line SLrst and the reference signal line SLcom.

The reference signal line SLcom is electrically coupled to the lowerconductive layer 35 through a contact hole H11. The reference signalline SLcom is also electrically coupled to the joint CA2 through acontact hole H12. This configuration electrically couples the referencesignal line SLcom to the p-type semiconductor layer 33 of each of thepartial photodiodes 30S.

In the present embodiment, the partial photodiode 30S is provided foreach of the first openings OP1 of the optical filter 7. Thisconfiguration can reduce portions of the semiconductor layers and wiringlayers in a region not overlapping the first openings OP1 as comparedwith a configuration in which the photodiode 30 is formed of a solidfilm having, for example, a quadrilateral shape so as to cover theentire detection element 3 in the plan view. Thus, the parasiticcapacitance of the photodiode 30 can be reduced. Since the multiplepartial photodiodes 30S are provided, the degree of freedom of thelayout of the transistors and the wiring can be increased, and thus, thetransistors and the wiring can be provided so as not to overlap thepartial photodiodes 30S. Consequently, in the present embodiment, theparasitic capacitance of the photodiode 30 can be smaller than that in acase of providing the photodiode 30 so as to overlap the transistors andthe wiring.

The planar structure of the photodiode 30 and the transistorsillustrated in FIG. 5 is merely an example and can be changed asappropriate. For example, the number of the partial photodiodes 30Sincluded in each of the photodiodes 30 may be seven or smaller, or nineof larger. The arrangement of the partial photodiodes 30S is not limitedto the triangular lattice pattern. The partial photodiodes 30S may bearranged, for example, in a matrix having a row-column configuration.

FIG. 6 is a VI-VI′ sectional view of FIG. 5. FIG. 7 is a VII-VII′sectional view of FIG. 5. FIG. 6 illustrates the sectional configurationof the partial photodiodes 30S-1, 30S-2, and 30S-7, and also thesectional configuration of the source follower transistor Msf includedin the detection element 3. FIG. 7 illustrates the sectionalconfiguration of the reset transistor Mrst. The read transistor Mrd (notillustrated in FIGS. 6 and 7) has the same sectional configuration asthat of the source follower transistor Msf and the reset transistorMrst.

As illustrated in FIG. 6, the substrate 21 is an insulating substrate,and is formed using, for example, a glass substrate of, for example,quartz or alkali-free glass, or a resin substrate of, for example,polyimide. The gate electrode 68 is provided on the substrate 21.Insulating films 22 and 23 are provided on the substrate 21 so as tocover the gate electrode 68. The insulating films 22 and 23 andinsulating films 24, 25, and 26 are inorganic insulating films and areformed of, for example, a silicon oxide (SiO₂) or a silicon nitride(SiN).

The semiconductor layer 65 is provided on the insulating film 23. Forexample, polysilicon is used as the semiconductor layer 65. Thesemiconductor layer 65 is, however, not limited thereto, and may beformed of, for example, a microcrystalline oxide semiconductor, anamorphous oxide semiconductor, or low-temperature polycrystallinesilicon (LTPS). The source follower transistor Msf has a bottom-gatestructure in which the gate electrode 68 is provided on the lower sideof the semiconductor layer 65. However, the source follower transistorMsf may have a top-gate structure in which the gate electrode 68 isprovided on the upper side of the semiconductor layer 65, or a dual-gatestructure in which the gate electrode 68 is provided on the upper sideor lower side of the semiconductor layer 65.

The semiconductor layer 65 has a channel region 65 a, high-concentrationimpurity regions 65 b and 65 c, and low-concentration impurity regions65 d and 65 e. The channel region 65 a is, for example, a non-dopedintrinsic semiconductor region or a low-impurity region, and has lowerconductivity than that of the high-concentration impurity regions 65 band 65 c and the low-concentration impurity regions 65 d and 65 e. Thechannel region 65 a is provided in a region overlapping the gateelectrode 68.

The insulating films 24 and 25 are provided on the insulating film 23 soas to cover the semiconductor layer 65. The source electrode 66 and thedrain electrode 67 are provided on the insulating film 25. The sourceelectrode 66 is coupled to the high-concentration impurity region 65 bof the semiconductor layer 65 through the contact hole H16. The drainelectrode 67 is coupled to the high-concentration impurity region 65 cof the semiconductor layer 65 through the contact hole H15. The sourceelectrode 66 and the drain electrode 67 are each formed of, for example,a multilayered film of Ti—Al—Ti or Ti—Al having a multilayered structureof titanium and aluminum.

As illustrated in FIG. 7, the reset transistor Mrst has the samesectional configuration as that of the source follower transistor Msfillustrated in FIG. 6. That is, the drain electrode 63 (coupling wiringSLcn3) is coupled to a high-concentration impurity region 61 c of thesemiconductor layer 61 through the contact hole H17. The insulating film26 is provided on the insulating film 25 so as to cover the transistorsincluding the reset transistor Mrst. The insulating film 27 is providedon the insulating film 26. The upper conductive layer 34 is provided onthe insulating film 27. The upper conductive layer 34 is electricallycoupled to the drain electrode 63 through the contact hole H4 providedthrough the insulating films 26 and 27.

Referring back to FIG. 6, the following describes the sectionalconfiguration of the photodiode 30. While the partial photodiodes 30S-1,30S-2, and 30S-7 are described using FIG. 6, the description of thepartial photodiodes 30S-1, 30S-2, and 30S-7 can also be applied to theother partial photodiodes 30S. As illustrated in FIG. 6, the lowerconductive layer 35 is provided in the same layer as that of the gateelectrode 68 on the substrate 21. The insulating films 22 and 23 areprovided on the lower conductive layer 35. The photodiode 30 is providedon the insulating film 23. In other words, the lower conductive layer 35is provided between the substrate 21 and the p-type semiconductor layer33. The lower conductive layer 35 is formed of the same material as thatof the gate electrode 68, and thereby serves as a light-blocking layer.Thus, the lower conductive layer 35 can restrain light from entering thephotodiode 30 from the substrate 21 side.

The i-type semiconductor layer 31 is provided between the p-typesemiconductor layer 33 and the n-type semiconductor layer 32 in thethird direction Dz. In the present embodiment, the p-type semiconductorlayer 33, the i-type semiconductor layer 31, and the n-typesemiconductor layer 32 are stacked on the insulating film 23 in theorder as listed.

Specifically, the p-type semiconductor layer 33 is provided in the samelayer as the semiconductor layers 61 and 65 on the insulating film 23.The insulating films 24, 25, and 26 are provided so as to cover thep-type semiconductor layer 33. The insulating films 24 and 25 areprovided with a contact hole H13 at a position overlapping the p-typesemiconductor layer 33. The insulating film 26 is provided on theinsulating film 25 and covers side surfaces of the insulating films 24and 25 constituting an inner wall of the contact hole H13. Theinsulating film 26 is provided with a contact hole H14 at a positionoverlapping the p-type semiconductor layer 33.

The i-type semiconductor layer 31 is provided on the insulating film 26,and is coupled to the p-type semiconductor layer 33 through the contacthole H14 penetrating from the insulating film 24 to the insulating film26. The n-type semiconductor layer 32 is provided on the i-typesemiconductor layer 31.

In more detail, the photodiode 30 has the first regions R1, secondregions R2 and a third region R3. The first regions R1 are providedcorresponding to the partial photodiodes 30S. In each of the firstregions R1, the p-type semiconductor layer 33, the i-type semiconductorlayer 31, and the n-type semiconductor layer 32 are stacked so as to bedirectly in contact with one another. In other words, the first regionR1 is a region defined by a bottom surface of the contact hole H14.

The second regions R2 are provided between the first regions R1. In eachof the second regions R2, at least the p-type semiconductor layer 33 andthe i-type semiconductor layer 31 are stacked so as to be separated fromeach other in a direction orthogonal to the substrate 21 (in the thirddirection Dz). More specifically, the second region R2 includes theinsulating films 24, 25, and 26 provided between the p-typesemiconductor layer 33 and the i-type semiconductor layer 31. The secondregion R2 is, however, not limited thereto, and may include one or twolayers of insulating films, or four or more layers of insulating filmsbetween the p-type semiconductor layer 33 and the i-type semiconductorlayer 31.

In the second region R2, the thickness of the insulating films 24, 25,and 26 (the total thickness of a thickness ti1 of the insulating films24 and 25 and a thickness ti2 of the insulating film 26) providedbetween the p-type semiconductor layer 33 and the i-type semiconductorlayer 31 is greater than a thickness ti3 of the i-type semiconductorlayer 31. The thickness ti1 of the insulating films 24 and 25 is greaterthan the thickness ti2 of the insulating film 26. The distance betweenthe p-type semiconductor layer 33 and the n-type semiconductor layer 32of the second region R2 is greater than the distance between the p-typesemiconductor layer 33 and the n-type semiconductor layer 32 of thefirst region R1. The thickness relation between the i-type semiconductorlayer 31 and the insulating films 24, 25, and 26 is not limited to theabove-described relation, and a configuration may be employed in whichthe total thickness of the three layers of the insulating films 24, 25,and 26 is less than the thickness of the i-type semiconductor layer 31.In the second region R2, the insulating films 24, 25, and 26 having apredetermined thickness need to be present between the i-typesemiconductor layer 31 (and/or the n-type semiconductor layer 32) andthe p-type semiconductor layer 33. However, various thicknesses can beemployed as the thickness of the insulating films 24, 25, and 26.

The second regions R2 are provided around the first regions R1 in theplan view and include the joints CA1, CA2 and the bases BA1 and BA2. Thepartial photodiodes 30S-1, 30S-2, and 30S-3 (FIG. 6 does not illustratethe partial photodiode 30S-3) are coupled to one another through thejoint CA1 including the i-type semiconductor layer 31 and the n-typesemiconductor layer 32 stacked on the insulating film 26 and the jointCA2 including the p-type semiconductor layer 33 formed on the insulatingfilm 23. In the same manner, the partial photodiodes 30S-4 to 30S-8(refer to FIG. 5) are coupled to one another through the base BA1including the i-type semiconductor layer 31 and the n-type semiconductorlayer 32 stacked on the insulating film 26 and the base BA2 includingthe p-type semiconductor layer 33 formed on the insulating film 23.

With the above-described configuration, the capacitance per unit areagenerated between the i-type semiconductor layer 31 and the p-typesemiconductor layer 33 in the second regions R2 is smaller than thecapacitance per unit area generated between the i-type semiconductorlayer 31 and the p-type semiconductor layer 33 in the first regions R1.Consequently, the capacitance Cs of each of the photodiodes 30 (refer toFIG. 4) can be reduced as compared with the configuration in which thephotodiode 30 is formed of a solid film having, for example, aquadrilateral shape so as to cover the entire detection element 3 in theplan view, that is, a configuration in which the i-type semiconductorlayer 31 and the n-type semiconductor layer 32 of the second regions R2are provided in the same layer the first regions R1. As a result, thedetection sensitivity of the detection device 1 can be improved. Thecapacitance generated between the i-type semiconductor layer 31 and thep-type semiconductor layer 33 has been described above. However, in viewof the fact that the i-type semiconductor layer 31 directly contacts then-type semiconductor layer 32, and the p-type semiconductor layer 33faces the n-type semiconductor layer 32 with the i-type semiconductorlayer 31 interposed therebetween, the above description of thecapacitance can naturally be replaced with a description of capacitancebetween the p-type semiconductor layer 33 and the n-type semiconductorlayer 32.

In the third region R3, the p-type semiconductor layer 33 is provided,and the i-type semiconductor layer 31 and the n-type semiconductor layer32 are provided so as not to overlap the p-type semiconductor layer 33.The third region R3 is a region provided with the joint CA2 aconstituted by the p-type semiconductor layer 33 described above. Thatis, in the third region R3, the adjacent second regions R2 are coupledto each other at least through the p-type semiconductor layer 33. Inaddition, in the third region R3, the insulating films 24 and 25 areprovided on the p-type semiconductor layer 33, and the reset signal lineSLrst and the reference signal line SLcom are provided on the insulatingfilms 24 and 25 provided on the p-type semiconductor layer 33. In otherwords, a gap SP of the i-type semiconductor layer 31 and the n-typesemiconductor layer 32 is provided above the reset signal line SLrst andthe reference signal line SLcom. Such a configuration can ensureinsulation between each of the signal lines and the n-type semiconductorlayer 32 as compared with a configuration in which the i-typesemiconductor layer 31 and the n-type semiconductor layer 32 areprovided so as to overlap the reset signal line SLrst and the referencesignal line SLcom.

The insulating film 27 is provided above the insulating film 26 so as tocover the photodiode 30. The insulating film 27 is provided so as to bedirectly in contact with the photodiode 30 and the insulating film 26.The insulating film 27 is formed of an organic material such as aphotosensitive acrylic resin. The insulating film 27 is thicker than theinsulating film 26. The thickness relation between these insulatingfilms may be reversed. The insulating film 27 has a better step coverageproperty than that of inorganic insulating materials, and is provided soas to cover side surfaces of the i-type semiconductor layer 31 and then-type semiconductor layer 32.

The upper conductive layer 34 is provided above the insulating film 27.The upper conductive layer 34 is formed of, for example, alight-transmitting conductive material such as indium tin oxide (ITO).The upper conductive layer 34 is provided along a surface of theinsulating film 27 and is coupled to the n-type semiconductor layer 32through the contact holes H1 and H3 provided in the insulating film 27.With this configuration, signals (photocurrents Ip) output from therespective partial photodiodes 30S are integrated in the common upperconductive layer 34 and are output as one detection signal Vdet throughthe source follower transistor Msf and the read transistor Mrd (refer toFIG. 4).

The contact hole H1 is provided at a position overlapping the firstregion R1. The n-type semiconductor layer 32 of the partial photodiode30S-1 is coupled to the upper conductive layer 34 on a bottom surface ofthe contact hole H1. Neither the contact hole H1 nor the contact hole H3is formed in the first regions R1 of the partial photodiodes 30S-2 and30S-7. The contact hole H3 is provided at a position overlapping thesecond region R2. The width of the first region R1 of the partialphotodiode 30S-1 is greater than the width of the first region R1 ofeach of the partial photodiodes 30S-2 and 30S-7. However, since theupper conductive layer 34 only needs to be coupled to the n-typesemiconductor layer 32 at any location, the first regions R1 of thepartial photodiodes 30S may be formed to have the same width and shape.

An insulating film 28 is provided on the insulating film 27 so as tocover the upper conductive layer 34. The insulating film 28 is aninorganic insulating film. The insulating film 28 is provided as aprotective layer for restraining water from entering the photodiode 30.

A protective film 29 is provided on the insulating film 28. Theprotective film 29 is an organic protective film. The protective film 29is formed so as to planarize a surface of the detection device 1.

In the present embodiment, the p-type semiconductor layer 33 and thelower conductive layer 35 of the photodiode 30 are provided in the samelayers as those of the transistors. Therefore, the manufacturing processcan be simpler than in a case where the photodiode 30 is formed inlayers different from those of the transistors.

The sectional configuration of the photodiode 30 illustrated in FIG. 6is merely an example. The sectional configuration is not limited to thisexample. For example, the photodiode 30 may be provided in layersdifferent from those of the transistors. The stacking order of thep-type semiconductor layer 33, the i-type semiconductor layer 31, andthe n-type semiconductor layer 32 is also not limited to that of FIG. 6.The stacking may be made in the order of the n-type semiconductor layer32, the i-type semiconductor layer 31, and the p-type semiconductorlayer 33.

The following describes a configuration example of the optical filter 7.FIG. 8 is a plan view illustrating a configuration example of theoptical filter and projections. FIG. 9 is a IX-IX′ sectional view ofFIG. 8. For ease of viewing, FIG. 8 illustrates projections PS withoblique lines added thereto. FIG. 9 illustrates a simplifiedconfiguration of the array substrate 2 and schematically illustrates thephotodiode 30 (partial photodiodes 30S-1 and 30S-6) and the protectivefilm 29 covering the photodiode 30.

The optical filter 7 is an optical element that transmits, toward thephotodiode 30, a component of the light L2 reflected by an object to bedetected such as the finger Fg that travels in the third direction Dz,and blocks components of the light L2 that travels in obliquedirections. The optical filter 7 is also called collimator apertures ora collimator.

As illustrated in FIG. 8, the optical filter 7 is provided so as tocover the detection elements 3 (photodiodes 30) arranged in a matrixhaving a row-column configuration. The optical filter 7 includes a firstlight-transmitting resin layer 74 (refer to FIG. 9) and a secondlight-transmitting resin layer 75 that cover the detection elements 3,and includes the lenses 78 provided for each of the detection elements3. The detection device 1 further includes the projections PS providedbetween the adjacent lenses 78.

The lenses 78 are arranged for each of the detection elements 3. In theexample illustrated in FIG. 8, eight lenses 78-1, 78-2, . . . , 78-8 areprovided for each of the detection elements 3. The lenses 78-1, 78-2, .. . , 78-8 are arranged in a triangular lattice pattern and are providedso as to overlap the partial photodiodes 30S-1, 30S-2, . . . , 30S-8,respectively.

The number of the lenses 78 arranged in each of the detection elements 3may be seven or smaller, or nine of larger so as to match the number ofthe partial photodiodes 30S. The arrangement of the lenses 78 can alsobe changed as appropriate depending on the configuration of thephotodiodes 30.

The projections PS are used as spacers when the array substrate 2 isstacked together with another substrate in the manufacturing process ofthe detection device 1. A method for manufacturing the detection device1 will be described later. Each of the projections PS has the same shapeas that of the lens 78 in the plan view and has a circular shape. Eachof the projections PS is provided so as to be surrounded by six of thelenses 78. More specifically, the projection PS is disposed between thelens 78-4 and the lens 78-5 in the second direction Dy, and theprojection PS is disposed between the lenses 78-1 and 78-3 and thelenses 78-6 and 78-8 in the first direction Dx. The projections PS arearranged with the lenses 78 in triangular lattice patterns and areefficiently arranged in spaces between the lenses 78.

The projection PS is provided at a boundary between the detectionelements 3 adjacent in the second direction Dy. In other words, theprojection PS is provided between the photodiodes 30 adjacent in thesecond direction Dy in the plan view. One projection PS is provided ateach of the boundaries between detection elements 3-1, 3-2, and 3-3arranged in the second direction Dy. One projection PS is provided ateach of the boundaries between detection elements 3-4, 3-5, and 3-6arranged adjacent to the detection elements 3-1, 3-2, and 3-3. Thenumber of the projections PS is smaller than the number of the lenses78. The projections PS are provided so as not to overlap the partialphotodiodes 30S of the photodiode 30.

The arrangement and the number of the projections PS can, however, bechanged as appropriate. For example, the projection PS may be providedat a boundary between the detection elements 3 adjacent in the firstdirection Dx. Although each of the detection elements 3 is provided withthe projection PS, one or more detection elements 3 not provided withthe projection PS may be present. The projection PS may have a differentshape and size from those of the lens 78.

As illustrated in FIG. 9, the optical filter 7 includes the firstlight-blocking layer 71, the second light-blocking layer 72, the firstlight-transmitting resin layer 74, the second light-transmitting resinlayer 75, and the lenses 78. In the present embodiment, the firstlight-blocking layer 71, the first light-transmitting resin layer 74,the second light-blocking layer 72, the second light-transmitting resinlayer 75, and the lenses 78 are stacked on the protective film 29 in theorder as listed. The projections PS are integrally formed with theoptical filter 7 and are provided in the same layer as that of thelenses 78 on the second light-transmitting resin layer 75.

The lenses 78 are respectively provided in regions overlapping thepartial photodiodes 30S of the photodiode 30. Each lens 78 is a convexlens. An optical axis CL of the lens 78 is provided in a directionparallel to the third direction Dz and intersects the partial photodiode30S. The lenses 78 are provided on the second light-transmitting resinlayer 75 so as to be directly in contact therewith. In other words, thesecond light-transmitting resin layer 75 is provided between the secondlight-blocking layer 72 and the lenses 78. In the present embodiment, nolight-blocking layer or the like is provided on the secondlight-transmitting resin layer 75 between the adjacent lenses 78.

The first light-blocking layer 71 and the second light-blocking layer 72are provided between the photodiode 30 and the lenses 78 in the thirddirection Dz. The first light-blocking layer 71 is provided with thefirst openings OP1 in regions overlapping the photodiode 30. The secondlight-blocking layer 72 is provided with the second openings OP2 inregions overlapping the photodiode 30. The lenses 78 are provided so asto overlap the first openings OP1 and the second openings OP2. In otherwords, the first openings OP1 and the second openings OP2 are formed inregions overlapping the optical axes CL.

The first light-blocking layer 71 is formed of, for example, a metalmaterial such as molybdenum (Mo). This material allows the firstlight-blocking layer 71 to reflect the components of the light L2traveling in the oblique directions other than the light L2 passingthrough the first opening OP1.

The second light-blocking layer 72 is formed of, for example, a resinmaterial colored in black. With this configuration, the secondlight-blocking layer 72 serves as a light-absorbing layer that absorbsthe components of the light L2 traveling in the oblique directions otherthan the light L2 passing through the second openings OP2. For example,the second light-blocking layer 72 can absorb light reflected by thefirst light-blocking layer 71 and extraneous light incident between theadjacent lenses 78.

In the present embodiment, the width decreases in the order of a widthW3 of the lens 78 in the first direction Dx, a width W2 of the secondopening OP2 in the first direction Dx, and the width W1 of the firstopening OP1 in the first direction Dx. The width W1 of the first openingOP1 in the first direction Dx is less than the width of the partialphotodiode 30S of the photodiode 30 in the first direction Dx.

A thickness TH2 of the second light-transmitting resin layer 75illustrated in FIG. 9 is set to be greater than a thickness TH1 of thefirst light-transmitting resin layer 74. The thickness TH1 of the firstlight-transmitting resin layer 74 and the thickness TH2 of the secondlight-transmitting resin layer 75 are greater than a thickness TH3 ofthe protective film 29 of the sensor substrate 5.

With the above-described configuration, light L2-1 traveling in thethird direction Dz among beams of the light L2 reflected by the objectto be detected such as the finger Fg is condensed by the lens 78, andpasses through the second opening OP2 and the first opening OP1 to enterthe photodiode 30. Light L2-2 tilted by an angle θ1 with respect to thethird direction Dz also passes through the second opening OP2 and thefirst opening OP1 to enter the photodiode 30.

The projections PS are provided at positions overlapping portions of thefirst light-blocking layer 71 not provided with the first openings OP1and portions of the second light-blocking layer 72 not provided with thesecond openings OP2. In other words, the projections PS overlap neitherthe first openings OP1 nor the second openings OP2, and the light L2having passed through the projections PS is blocked by the firstlight-blocking layer 71 and the second light-blocking layer 72. That is,although the detection device 1 has the configuration provided with theprojections PS, the detection device 1 can restrain the detectionaccuracy from decreasing.

A width W4 (diameter) in the first direction Dx of the projection PS isequal to a width W3 (diameter) in the first direction Dx of the lens 78.In the third direction Dz, a height HE1 of the projection PS is greaterthan a height HE2 of the lens 78. In other words, when viewed from afirst principal surface MS1 of the substrate 21 (refer to FIG. 12), thetop of the projection PS is provided at a position higher than the topof the lens 78. The overall length from the top to the bottom of theprojection PS is greater than the overall length from the top to thebottom of the lens 78. The height HE1 of the projection PS is in a rangefrom 1.0 μm to 5.5 μm, and is, for example, approximately or exactly3.75 μm. The height HE2 of the lens 78 is in a range from 0.5 μm to 5.0μm, and is, for example, approximately or exactly 3.0 μm. The projectionPS is formed of a resin material and is patterned into a columnar shapeusing a photolithography technique. In FIG. 9, the upper surface of theprojection PS is formed flat. FIG. 9 is, however, a sectional viewmerely schematically illustrated. The upper surface of the projection PSmay have a curved surface in the same manner as the lens 78.

The optical filter 7 is integrally formed with the array substrate 2.That is, the first light-blocking layer 71 of the optical filter 7 isprovided on the protective film 29 so as to be directly in contacttherewith, and any member such as an adhesive layer is not providedbetween the first light-blocking layer 71 and the protective film 29.The optical filter 7 is directly formed as a film on the array substrate2 and is formed by being subjected to a process such as patterning.Consequently, the positional accuracy of the first opening OP1, thesecond opening OP2, and the lens 78 of the optical filter 7 with respectto the photodiode 30 can be improved as compared with the case ofattaching the optical filter 7 as a separate component to the arraysubstrate 2.

The configuration of the optical filter 7 illustrated in FIG. 9 ismerely an example and can be changed as appropriate. For example, theoptical filter 7 may be formed separately from the array substrate 2.The relations between the widths W1, W2, and W3 and between thethicknesses TH1, TH2, and TH3 may be changed as appropriate depending onrequired optical characteristics. The optical filter 7 is not limited tothe configuration provided with the first light-blocking layer 71 andthe second light-blocking layer 72 and may be provided with one layer ofthe first light-blocking layer 71 and one layer of the firstlight-transmitting resin layer 74.

The following describes the method for manufacturing the detectiondevice 1. FIG. 10 is a flowchart for explaining the method formanufacturing the detection device according to the embodiment. FIG. 11is a perspective view schematically illustrating a pair of bondedmotherboards. FIG. 12 is a XII-XII′ sectional view of FIG. 11. For easeof viewing, FIG. 12 does not illustrate a detailed configuration of thearray substrate 2 and illustrates an example of two of the partialphotodiodes 30S and two of the lenses 78 arranged so as to face eachother.

As illustrated in FIG. 10, manufacturing equipment forms the photodiodes30 (Step ST1). Specifically, a pair of motherboards 105 (refer to FIG.11) are prepared, and after various transistors and various types ofwiring are formed on each of the motherboards 105, the photodiodes 30each including the partial photodiodes 30S are formed. As illustrated inFIG. 11, a plurality of sensor regions 106 are arranged on themotherboard 105. The sensor regions 106 are regions each to be formed asthe detection device 1 (array substrate 2) when being divided into diesalong dividing lines 108 and 109. That is, a multilayered structure fromthe substrate 21 to the optical filter 7 and the projections PS isformed on the motherboard 105, which includes the transistors, thevarious types of wiring, and the photodiodes 30.

The manufacturing equipment then forms the first light-blocking layer 71and the second light-blocking layer 72 above the protective film 29covering the photodiodes 30 (Step ST2). Specifically, the manufacturingequipment forms the first light-blocking layer 71 on the protective film29 and patterns the first openings OP1 at positions overlapping thepartial photodiodes 30S. Then, the first light-transmitting resin layer74 is applied to be formed on the first light-blocking layer 71. Thesecond light-blocking layer 72 is formed on the first light-transmittingresin layer 74, and the second openings OP2 are patterned at positionsoverlapping the partial photodiodes 30S. The second light-transmittingresin layer 75 is formed on the second light-blocking layer 72.

The manufacturing equipment then forms the lenses 78 (Step ST3). Thelenses 78 having curved surface shapes are formed by applying a resinmaterial on the second light-transmitting resin layer 75, performingpatterning using the photolithography technique, and performing baking.

Then, the projections PS are formed between the adjacent lenses 78 (StepST4). The resin material is applied on the second light-transmittingresin layer 75 to form the projections PS having a thickness greaterthan that of the lenses 78. The projections PS are patterned using thephotolithography technique and are baked to be hardened. The projectionsPS are preferably formed using a material different from that of thelenses 78 but may be formed using the same material as that of thelenses 78. For example, a transparent acrylic resin or siloxane resin isused as the material of the lenses 78. For example, a transparentacrylic resin, epoxy resin, or polyimide is used as the material of theprojections PS.

Then, the pair of motherboards 105 are stacked together (Step ST5).Specifically, as illustrated in FIGS. 11 and 12, the manufacturingequipment bonds the pair of motherboards 105 together in such a mannerthat the first principal surfaces MS1 of the substrates 21 of the pairof motherboards 105, on which the photodiodes 30 (FIG. 12 illustratesone of the partial photodiodes 30S), the lenses 78, and the projectionsPS are formed, face each other. This operation causes the projections PSprovided on the surfaces of the second light-transmitting resin layers75 to be disposed between the first principal surfaces MS1 of the pairof substrates 21. A second principal surface MS2 of each of the pair ofsubstrates 21 is directed outward in the third direction Dz.

As illustrated in FIG. 12, the pair of motherboards 105 are stackedtogether such that the projections PS of one motherboard 105-1 abut onthe projections PS of the other motherboard 105-2. As a result, a gap107 is formed between the first principal surfaces MS1 of the pair ofsubstrates 21, and thus, the lenses 78 facing each other can berestrained from contacting each other. Terminals 90 provided on thefirst principal surfaces MS1 of the pair of substrates 21 are alsodisposed facing with a gap interposed therebetween. Each of theterminals 90 is a terminal for electrically coupling the array substrate2 to the external wiring substrate 110 (refer to FIG. 2). The pair ofmotherboards 105 are bonded together by a seal 51 provided in aperipheral region 105P. The seal 51 is provided so as to surround thesensor regions 106, and seals a gap between the pair of substrates 21.

In FIG. 12, the pair of motherboards 105 are stacked together such thatthe positions of the projections PS of the one motherboard 105-1 fullymatches the positions of the projections PS of the other motherboard105-2. However, the present disclosure is not limited to thisconfiguration. The projections PS of the one motherboard 105-1 only needto be provided so as to at least partially overlap the projections PS ofthe other motherboard 105-2.

Referring back to FIG. 10, the manufacturing equipment then polishes thesecond principal surface MS2 of each of the pair of substrates 21 in thestate where the pair of motherboards 105 are stacked together (StepST6). Chemical polishing is employed to polish the substrates 21.Mechanical polishing may be employed to polish the substrates 21. Thesecond principal surface MS2 side of each of the pair of substrates 21is removed from the substrate 21 having the original thickness (at thesecond principal surface MS2 indicated by a solid line in FIG. 12), andthus, the substrate 21 is thinned to the second principal surface MS2indicated by a long dashed double-short dashed line in FIG. 12. In thismanner, in the present embodiment, one operation of the polishingprocess can simultaneously polish the pair of substrates 21.

Accordingly, the method for manufacturing the detection device 1according to the present embodiment can reduce the manufacturing cost ascompared with a case where the optical filter 7 side of the singlesubstrate 21 (motherboard 105) is bonded onto another supportingsubstrate, and the substrate 21 is polished. In addition, since thepolishing process can be performed in the state where the lenses 78 ofthe optical filter 7 do not contact other members, the substrate 21 canbe thinned while reducing damage to the lenses 78.

The manufacturing equipment then separates the pair of motherboards 105(Step ST7). Specifically, the seal 51 is removed by cutting an outeredge portion of the pair of motherboards 105 along the inside of theseal 51. Through performing this operation, a portion of the pair ofmotherboards 105 in which the sensor regions 106 are formed is separatedfrom the seal 51, and thus, the pair of motherboards 105 can beseparated.

In the present embodiment, since the projections PS form the gap 107between the pair of substrates 21, air easily enters the gap 107 whenthe pair of motherboards 105 are caused to be separated, and thereby, aseparation process can be easily performed. That is, even when thesubstrates 21 have been thinned by the polishing process, the separationprocess of the pair of motherboards 105 can be easily performed, and thesubstrates 21 can be restrained from being damaged. Thus, the method formanufacturing the detection device 1 can thin the detection device 1while restraining the manufacturing cost from increasing.

The manufacturing equipment then divides each of the motherboards 105(105-1 and 105-2) into dies (Step ST8). Specifically, the motherboards105 are divided into the sensor regions 106 along the dividing lines 108and 109 illustrated in FIG. 11 to form the array substrates 2. Then, thedetection device 1 can be manufactured by bonding the cover member 122and the display panel 126 to each of the array substrates 2 as required.FIG. 13 is a sectional view schematically illustrating a configurationof the array substrate bonded to the display panel. As illustrated inFIG. 13, the substrate 21 is bonded to the display panel 126 such thatthe projections PS abut on the lower surface of the display panel 126.This configuration restrains the lenses 78 in the detection device 1from contacting the display panel 126, thereby restraining the lenses 78from being damaged.

The method for manufacturing the detection device 1 illustrated in FIGS.10 to 12 is schematically illustrated for facilitating understanding ofthe description, and may be changed as appropriate. For example, whilethe sensor regions 106 of the motherboards 105 are arranged in threerows and five columns, 16 or more sensor regions 106 may actually beprovided. Although FIG. 12 illustrates the terminal 90 in the same layeras that of the partial photodiode 30S, the terminal 90 may be formed ina layer different from that of the partial photodiode 30S.

As described above, the detection device 1 of the present embodimentincludes the substrate 21, the photodiodes 30 arranged on the firstprincipal surface MS1 of the substrate 21, the protective film 29covering the photodiodes 30, the lenses 78 provided for each of thephotodiodes 30 so as to face the photodiode 30 with the protective film29 interposed therebetween, and the projections PS provided between theadjacent lenses 78. When viewed from the first principal surface MS1,the top of the projection PS is provided at the position higher than thetop of the lens 78.

The method for manufacturing the detection device 1 according to thepresent embodiment includes the process of stacking the pair ofsubstrates 21 together, with the first principal surfaces MS1 of thepair of substrates 21, on which the projections PS having the height HE1in the direction orthogonal to the substrates 21 greater than the heightHE2 of the lenses 78, facing each other (Step ST5) and the process ofpolishing the second principal surface MS2 on the opposite side of thefirst principal surface MS1 of each of the pair of substrates 21 in thestate where the substrates 21 are stacked together (Step ST6). In theprocess of stacking the pair of substrates 21 together, the projectionsPS of one of the detection devices 1 abut on portions of the other ofthe detection devices 1 facing the one detection device, and the lenses78 of the detection devices 1 face each other without contacting eachother.

FIG. 14 is a flowchart for explaining a method for manufacturing thedetection device according a fourth modification of the embodiment. Inthe following description, the same components as those described in theabove-described embodiment are denoted by the same reference numerals,and the description thereof will not be repeated.

As illustrated in FIG. 14, in the fourth modification, the manufacturingequipment forms the lenses 78 and the projections PS in the same process(Step ST11). The lenses 78 and the projections PS are formed by applyinga resin material on the second light-transmitting resin layer 75,performing patterning using the photolithography technique, andperforming baking. The lenses 78 and the projections PS may be formed tohave the different heights HE1 and HE2 by being patterned, for example,using a half-exposure technique. This method allows the fourthmodification to eliminate one manufacturing process as compared with theabove-described embodiment. Steps ST1, ST2, and ST5 to ST8 are the sameas the processes illustrated in FIG. 10.

FIG. 15 is a sectional view schematically illustrating a detectiondevice according a fifth modification of the embodiment. As illustratedin FIG. 15, in an optical filter 7A of a detection device 1A accordingto the fifth modification, the projection PS includes a first projectionPSA and a second projection PSB. The first projection PSA is provided inthe same layer as that of the lens 78 on the second light-transmittingresin layer 75. The second projection PSB is provided so as to overlapthe first projection PSA.

The first projection PSA is formed using the same material as that ofthe lens 78 in the same process as that of the lens 78 at Step ST3illustrated in FIG. 10. The second projection PSB is formed above thefirst projection PSA using a material different from that of the lens 78in the same process as Step ST4 illustrated in FIG. 10. That is, amethod for manufacturing the detection device 1A of the fifthmodification includes a process of forming the lens 78 and the firstprojection PSA in the same layer as that of the lens 78 (Step ST3), anda process of forming the second projection PSB so as to overlap thefirst projection PSA (Step ST4). The second projection PSB is formed soas to cover the entire first projection PSA and has the same width(diameter) as the width W4 of the first projection PSA.

In the present modification, the height of the projection PS is thetotal height of a height HE3 of the first projection PSA and a heightHE4 of the second projection PSB. Thus, the projection PS can be easilyformed to be higher than the height HE2 of the lens 78.

FIG. 16 is a sectional view schematically illustrating a detectiondevice according a sixth modification of the embodiment. As illustratedin FIG. 16, in an optical filter 7B of a detection device 1B accordingto the sixth modification, a width W5 (diameter) of the secondprojection PSB is less than the width W4 (diameter) of the firstprojection PSA. In other words, the second projection PSB is formed soas to project from the upper surface of the first projection PSA. Inthis manner, the first projection PSA and the second projection PSB mayhave different shapes and sizes.

The relation between the sizes of the first projection PSA and thesecond projection PSB is not limited to the example illustrated in FIG.16 and may be reversed such that the width W5 (diameter) of the secondprojection PSB is greater than the width W4 (diameter) of the firstprojection PSA. For example, the width W4 of the first projection PSAmay be set to be less than the width W3 of the lens 78, and the secondprojection PSB may be formed to have the same width as the width W3 ofthe lens 78 so as to cover the entire first projection PSA.

FIG. 17 is a plan view schematically illustrating a detection deviceaccording a seventh modification of the embodiment. In FIG. 17illustrating a case where the pair of motherboards 105 are stackedtogether (refer to FIG. 11), projections PSC provided on the onemotherboard 105-1 are illustrated with oblique lines added thereto, andthe projections PSC provided on the other motherboard 105-2 areillustrated with long dashed double-short dashed lines.

As illustrated in FIG. 17, in an optical filter 7C of a detection device1C according to the seventh modification, each of the projections PSC isformed to have a shape and size different from those of the lens 78. Theprojection PSC has a rectangular shape in a plan view as viewed from thethird direction Dz. A direction along a long side of the projection PSCis slanted along a direction intersecting the first direction Dx and thesecond direction Dy. The shape of the projection PSC is not limited tothe rectangular shape and may be an oval or an elliptical shape.

When the pair of motherboards 105 are stacked together, the projectionPSC provided on the one motherboard 105-1 and the projection PSCprovided on the other motherboard 105-2 are arranged so as to intersecteach other. That is, the projections PSC are provided so as to at leastpartially contact each other.

In the seventh modification, even when spaces for providing theprojections PSC are smaller, or lenses 78 are arranged more densely thanin the above-described embodiment, the projections PSC can be providedin regions not overlapping the lenses 78 and the partial photodiodes30S. In addition, the projection PSC is provided such that the directionalong the long side of the projection PSC is slanted with respect to thefirst direction Dx and the second direction Dy. This configuration canensure an overlapping area of the pair of projections PSC even ifmisalignment in position occurs when the pair of motherboards 105 arestacked together.

FIG. 18 is a plan view schematically illustrating a detection deviceaccording an eighth modification of the embodiment. FIG. 19 is asectional view for explaining a method for manufacturing the detectiondevice according the eighth modification. In FIG. 18 illustrating a casewhere the pair of motherboards 105 are stacked together (refer to FIG.19), the projections PSC provided on the one motherboard 105-1 areillustrated with oblique lines added thereto, and the projections PSCprovided on the other motherboard 105-2 are illustrated with long dasheddouble-short dashed lines.

As illustrated in FIG. 18, in an optical filter 7D of a detection device1D according to the eighth modification, projections PSD are arrangedone for every two detection elements 3 arranged in the second directionDy. For example, on the one motherboard 105-1, the projection PSD is notprovided at a boundary between the detection element 3-1 and thedetection element 3-2, and the projection PSD is provided at a boundarybetween the detection element 3-2 and the detection element 3-3. Thatis, in one detection element column in which the detection elements 3are arranged in the second direction Dy, the projection PSD is providedfor every other boundary between the detection elements. In anotherdetection element column adjacent to the one detection element column,the projection PSD is provided for every other boundary between thedetection elements 3, in the same manner as the one detection elementcolumn. However, the forming positions of the projections PSD aredifferent between the adjacent detection element columns. In otherwords, in the adjacent detection element columns, the projections PSDare arranged in a staggered manner.

On the other motherboard 105-2, the projection PSD is provided at theboundary between the detection element 3-1 and the detection element3-2, and the projection PSD is not provided at the boundary between thedetection element 3-2 and the detection element 3-3. That is, when thepair of motherboards 105 are stacked together, the projections PSDprovided on the one motherboard 105-1 and the projections PSD providedon the other motherboard 105-2 are alternately arranged in the firstdirection Dx and the second direction Dy, and are thus provided atpositions not overlapping each other, in the plan view.

As illustrated in FIG. 19, when the pair of motherboards 105 are stackedtogether, the projection PSD (PSD-1) of the one motherboard 105-1 abutson a portion of the second light-transmitting resin layer 75 of theother motherboard 105-2 that is not provided with the lens 78. In thesame manner, the projection PSD (PSD-2) of the other motherboard 105-2abuts on a portion of the second light-transmitting resin layer 75 ofthe one motherboard 105-1 that is not provided with the lens 78. Also inthe eighth modification, the gap 107 is formed between the lens 78 ofthe one motherboard 105-1 and the lens 78 of the other motherboard105-2.

In the present modification, the projections PSD are formed to behigher, and the number of the projections PSD per unit area is smallerthan in the above-described embodiment. In addition, since theprojections PSD need not be arranged so as to overlap each other whenthe pair of motherboards 105 are stacked together, the allowable degreeof misalignment in position between the pair of motherboards 105 can beincreased.

The above-described modifications can be combined with one another. Forexample, the projection PSC illustrated in the seventh modification andthe projection PSD illustrated in the eighth modification may each becombined with the fifth or the sixth modification. That is, theprojections PSC and PSD can each have a structure obtained by stackingtwo layers of projections.

While the preferred embodiment of the present disclosure has beendescribed above, the present disclosure is not limited to the embodimentdescribed above. The content disclosed in the embodiment is merelyexemplary, and can be variously changed within the scope not departingfrom the gist of the present disclosure. Any modification appropriatelymade within the scope not departing from the gist of the presentdisclosure also naturally belongs to the technical scope of the presentdisclosure. At least one of various omissions, replacements, andmodifications of the components can be made without departing from thegist of the embodiment and the modifications thereof described above.

What is claimed is:
 1. A detection device comprising: a substrate; aplurality of photodiodes arranged on a first principal surface of thesubstrate; a protective film that covers the photodiodes; a plurality oflenses provided for each of the photodiodes so as to face the photodiodewith the protective film interposed between the lenses and thephotodiodes; and a projection provided between the lenses, wherein a topof the projection is located at a position higher than a top of each ofthe lenses when viewed from the first principal surface.
 2. Thedetection device according to claim 1, comprising: a light-blockinglayer that is provided between the photodiodes and the lenses and isprovided with openings in regions overlapping the respectivephotodiodes; and a light-transmitting resin layer provided between thelight-blocking layer and the lenses, wherein the lenses and theprojection are provided on the light-transmitting resin layer, and thelenses overlap the openings, and the projection overlaps a region of thelight-blocking layer where the openings are not formed.
 3. The detectiondevice according to claim 2, wherein the projection is higher than aheight of the lenses in a direction orthogonal to the first principalsurface.
 4. The detection device according to claim 1, wherein anoverall length from the top to a bottom of the projection is greaterthan an overall length from the top to a bottom of the lens.
 5. Thedetection device according to claim 1, wherein the projection includes afirst projection provided in same layer as a layer of the lenses, and asecond projection provided so as to overlap the first projection.
 6. Thedetection device according to claim 5, wherein the first projection isformed of the same material as that of the lenses.
 7. The detectiondevice according to claim 5, wherein a diameter of the second projectionis equal to a diameter of the first projection.
 8. The detection deviceaccording to claim 5, wherein a diameter of the second projection isless than a diameter of the first projection.
 9. The detection deviceaccording to claim 1, wherein the projection has the same shape as ashape of the lenses in a plan view from a direction orthogonal to thesubstrate.
 10. The detection device according to claim 1, wherein eachof the photodiodes includes a plurality of partial photodiodes, in eachof which a p-type semiconductor layer, an i-type semiconductor layer,and an n-type semiconductor layer are staked, the lenses are provided soas to overlap the respective partial photodiodes, and the number of theprojections is smaller than the number of the lenses.
 11. The detectiondevice according to claim 10, wherein the substrate has a detectionregion that is divided into a plurality of detection elements each ofwhich is provided with one or more of the partial photodiodes, thelenses are provided so as to overlap the partial photodiodes in thedetection electrodes, and the projection is provided at a boundarybetween adjacent detection elements of the detection elements.
 12. Thedetection device according to claim 11, wherein the projection isprovided at a boundary between detection elements arranged in a firstdirection, of the detection elements.
 13. The detection device accordingto claim 12, wherein in one detection element column in which thedetection elements are arranged in the first direction in the detectionregion, the projection is provided for every other boundary between thedetection elements.
 14. The detection device according to claim 13,wherein in another detection element column adjacent to the onedetection element column, the projection is provided for every otherboundary between the detection elements, and in the adjacent twodetection element columns, the projections are arranged in a staggeredmanner
 15. A method for manufacturing a detection device, the detectiondevice comprising a substrate, a plurality of photodiodes arranged on afirst principal surface of the substrate, a protective film provided onthe substrate so as to cover the photodiodes, and a plurality of lensesprovided for each of the photodiodes so as to overlap the photodiode,the method comprising: stacking a pair of the substrates together, withthe first principal surfaces of the pair of the substrates facing eachother, the substrates each having a projection formed on the substrate,the projection having a height greater than a height of the lenses in adirection orthogonal to the substrate; and polishing a second principalsurface on an opposite side of the first principal surface of each ofthe substrates in a state where the pair of the substrates are stackedtogether, wherein at the stacking the pair of the substrates together,the projection of one of the detection devices abuts on a portion ofanother of the detection devices facing the one detection device, andthe lenses of the one detection device face the lenses of the otherdetection device without contacting one another.
 16. The methodaccording to claim 15, wherein, in the state where the pair of thesubstrates are stacked together, at least a part of the projectionprovided on one of the substrates is arrange so as to abut on theprojection provided on another of the substrates.
 17. The methodaccording to claim 15, comprising: forming the lenses; and forming theprojection between the lenses adjacent to each other.
 18. The methodaccording to claim 15, comprising forming the lenses and the projection.19. The method according to claim 15, comprising: forming the projectionincluding forming the lenses and a first projection in same layer as alayer of the lenses; and forming a second projection so as to overlapthe first projection.
 20. The method according to claim 15, wherein,when the pair of the substrates are stacked together, the projectionprovided on one of the substrates and the projection provided on anotherof the substrates are alternately arranged.